import _00GraphFuc as gf

##13.3验证欧拉公式
V={0,1,2,3,4,5,6}
E={(0,1),(1,2),(2,3),(3,4),(4,5),(5,6),(6,0),(0,5),(1,3),(1,5),(3,5)}
gf.drawgraph(E)
print(len(V)-len(E)+6)